//:C05:Box2.cpp
// Defines non-template operators.
#include <iostream>
using namespace std;
template<class T> class Box
{
    T t;
    public:
        Box(const T& theT) : t(theT){}
        friend Box<T> operator+(const Box<T>& b1,
                const Box<T>& b2)
        {
            return Box<T>(b1.t + b2.t);
        }
        friend ostream& operator<<(ostream& os, const Box<T>& b)
        {
            return os << '[' << b.t << ']';
        }
};

int main(void)
{
    Box<int> b1(1), b2(2);
    cout << b1 + b2 << endl;   // [3]
    cout << b1 + 2 << endl;    // [3]
}
